Pretty sure it was 2.25 inlet and 3.5 outlet. As I recall, the issue was we didn't have the car in our possession yet and I wanted to order the tips ahead of time. When the car and the tips arrived, the tip inlet size was too big. I think you told me 2.5 at that time. I can't guarantee this..... but I am fairly confident it's a 2.25 Inlet and 3.5 Outlet. So what you're looking at is 3.5 from the rear of the car.